The Third edition brings the translation of technical terms into line with the other volumes of Frege's work now available in English. Uniform translations of Frege's terms helps to bring out the continuity of his thought throughout his creative years. Since it now appears in its rightful place in Frege's Logical Investigations, the essay on 'Negation' has been omitted from this edition. The addition of an index further enhances the usefulness of the volume.